How can i learn logic & proof on geometry? my teacher seems not know how to do her job!

What is the square root of 45? (step by step working plz)

Which measure is equivalent to 110 ml? 0.0110 l 0.110 l 1.10 l 11,000 l

Arestaurant offers a $12 dinner special that has 5 choices for an appetizer, 12 choices for an entrée, and 4 choices for a dessert. how many different meals are available when you select an appetizer, an entrée, and a dessert? a meal can be chosen in nothing ways. (type a whole number.)